New Secretary of State for Wales Stephen Crabb once thought the job he now holds should be abolished.

Seven years ago, when he was the recently-elected MP for Preseli Pembrokeshire, he wrote a scathing analysis of devolution for the Conservative Home website, in which he wrote: “Reform of the relevant Whitehall machinery is also necessary.

"The roles of Secretary of State for Scotland, Wales and (to a lesser extent) Northern Ireland have become emptied and somewhat meaningless under devolution. Peter Hain did two of the jobs for almost three years.

"Throw in Scotland as well and we can have one streamlined Department of Celtic Affairs. A reduction in the number of MPs in Wales and Scotland would go hand-in-hand with this.”

Mr Crabb’s piece, headlined “The devolution experiment is leading to socialism and separatism”, did back a measure of fiscal devolution, saying: “A future Conservative Government could even look at some form of limited fiscal devolution to create the impression of a fairer and more responsible devolved system”.

However, it concluded: “But I am not convinced that a re-balancing of the one-way devolution project will ultimately make it safe.

“Together with uncontrolled immigration and relentless European integration, devolution has the potential to cause huge and permanent damage to our country. The United Kingdom is being slowly dismembered and hollowed-out in full view, and with the tacit consent, of the political classes.

“By creating multiple and competing poles of national authority and decision-making, and by financing them in such an egregiously unfair way, {Gordon} Brown and his Labour colleagues have sown the seeds of deep division and resentment and set in motion the break-up of the Union.”